Bloom: A Language For Disorderly Distributed Programming

Transcript

1. Bloom: A Language For Disorderly Distributed Programming Christopher Meiklejohn Wicked

   Good Ruby ’13 Sunday, October 13, 13

2. cmeiklejohn / @cmeik My Name is My Name Sunday, October

   13, 13

3. What do you do? Sunday, October 13, 13

4. Sunday, October 13, 13

5. Sunday, October 13, 13

6. Sunday, October 13, 13

7. What did you do? Sunday, October 13, 13

8. Sunday, October 13, 13

9. Sunday, October 13, 13

10. UC Berkeley Sunday, October 13, 13

11. BOOM Sunday, October 13, 13

12. The Outline Sunday, October 13, 13

13. Theory, language. The Outline Sunday, October 13, 13

14. von Neumann Sunday, October 13, 13

15. Instructions, mutable state, executed in order. von Neumann Sunday, October

    13, 13

16. Imposes a total order. von Neumann Sunday, October 13, 13

17. Disorderly actors Sunday, October 13, 13

18. Allow disorder and races; illusion of total order. Disorderly actors

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19. The idea behind transactions; serializability. Disorderly actors Sunday, October 13,

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20. Tricky to scale. Disorderly actors Sunday, October 13, 13

21. Scaling Sunday, October 13, 13

22. Multiple machines; sharing computation. Scaling Sunday, October 13, 13

23. CAP Theorem Sunday, October 13, 13

24. Consistency, availability, partition tolerance. CAP Theorem Sunday, October 13, 13

25. Negative result: linearizability impossible. CAP Theorem Sunday, October 13, 13

26. Whoa, Theory! Sunday, October 13, 13

27. Distributed computing Sunday, October 13, 13

28. The “new normal”. Distributed computing Sunday, October 13, 13

29. Order is di!cult to impose. Distributed computing Sunday, October 13,

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30. Synchronization; coordination. Distributed computing Sunday, October 13, 13

31. FLP result; delays, partitions, partial writes. Distributed computing Sunday, October

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32. Inverse methods; commutative operations. Distributed computing Sunday, October 13, 13

33. ACID 2.0 Sunday, October 13, 13

34. Associativity, commutativity, idempotence. ACID 2.0 Sunday, October 13, 13

35. (X · Y) · Z = X · (Y ·

    Z) ACID 2.0: Associativity Sunday, October 13, 13

36. X · Y = Y · X ACID 2.0: Commutativity

    Sunday, October 13, 13

37. X · X = X ACID 2.0: Idempotence Sunday, October

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38. Associativity, commutativity, idempotence. ACID 2.0 Sunday, October 13, 13

39. Familiar? Sunday, October 13, 13

40. Bounded Join Semilattices Sunday, October 13, 13

41. Partially ordered set; least upper bound; ACI. Bounded Join Semilattices

    Sunday, October 13, 13

42. Objects grow over time; merge computes LUB. Bounded Join Semilattices

    Sunday, October 13, 13

43. Monotonic and con"uent; convergent. Bounded Join Semilattices Sunday, October 13,

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44. Map into another via monotone functions. Bounded Join Semilattices Sunday,

    October 13, 13

45. Examples. Bounded Join Semilattices Sunday, October 13, 13

46. b a c a, b a, c a, b, c

    Set; merge function: union. b, c Sunday, October 13, 13

47. 3 5 7 5 7 7 Increaing natual; merge function:

    max. Sunday, October 13, 13

48. F F T F T T Booleans; merge function: or.

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49. x <= y montone f(x) <= f(y) Sunday, October 13,

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50. Sunday, October 13, 13

51. CvRDT examples. Sunday, October 13, 13

52. [ [{1, a}], [] ] [ [{1, a}], [] ]

    Sunday, October 13, 13

53. [ [{1, a}], [] ] [ [{1, a}], [] ]

    [ [{1, a}], [{1, a}] ] [ [{1, a}], [{1, a}] ] Sunday, October 13, 13

54. [ [{1, a}], [] ] [ [{1, a}], [] ]

    [ [{1, a}], [{1, a}] ] [ [{1, a}], [{1, a}] ] [ [{1, a}, {2, a}], [{1, a}] ] Sunday, October 13, 13

55. [ [{1, a}], [] ] [ [{1, a}], [] ]

    [ [{1, a}], [{1, a}] ] [ [{1, a}], [{1, a}] ] [ [{1, a}, {2, a}], [{1, a}] ] [ [{1, a}, {2, a}], [{1, a}] ] Sunday, October 13, 13

56. [ [{1, a}], [] ] [ [{1, a}], [] ]

    Sunday, October 13, 13

57. [ [{1, a}], [] ] [ [{1, a}], [] ]

    [ [{1, a}, {2, b}], [] ] Sunday, October 13, 13

58. [ [{1, a}], [] ] [ [{1, a}], [] ]

    [ [{1, a}, {2, b}], [] ] [ [{1, a}], [{1, a}] ] Sunday, October 13, 13

59. [ [{1, a}], [] ] [ [{1, a}], [] ]

    [ [{1, a}, {2, b}], [] ] [ [{1, a}], [{1, a}] ] [ [{1, a}, {2, b}], [{1, a}] ] Sunday, October 13, 13

60. Just data; what about computation? Bounded Join Semilattices Sunday, October

    13, 13

61. Composability desired. Bounded Join Semilattices Sunday, October 13, 13

62. CALM Theorem Sunday, October 13, 13

63. Consistency as Logical Monotonicity CALM Theorem Sunday, October 13, 13

64. Consistent given async; all monotone functions. CALM Theorem Sunday, October

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65. Identify non-monotone functions. CALM Theorem Sunday, October 13, 13

66. Disorderly Programming Sunday, October 13, 13

67. Order-independent, explicit order-dependent. Disorderly Programming Sunday, October 13, 13

68. Prototype language: Bloom Disorderly Programming Sunday, October 13, 13

69. Bloom Sunday, October 13, 13

70. Based in a logic called Dedalus. Bloom Sunday, October 13,

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71. Disorderly language. Bloom Sunday, October 13, 13

72. Lattices and mappings between lattices. Bloom Sunday, October 13, 13

73. Highlights non-monotonicity. Bloom Sunday, October 13, 13

74. Operational model. Bloom Sunday, October 13, 13

75. Local clock; local execution; local state. Bloom Sunday, October 13,

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76. Timestepped execution. Bloom Sunday, October 13, 13

77. Local updates; system events; network. Sunday, October 13, 13

78. Bloom rules; merge functions. Sunday, October 13, 13

79. Network; next. Sunday, October 13, 13

80. Chat server. Bloom Sunday, October 13, 13

81. module ChatProtocol state do channel :connect, [:@addr, :client] => [:nick]

    channel :mcast end end examples/chat/chat_protocol.rb Sunday, October 13, 13

82. class ChatServer include Bud include ChatProtocol state { table :nodelist

    } bloom do nodelist <= connect.map { |c| [c.client, c.nick] } mcast <~ (mcast * nodelist).pairs { |m,n| [n.key, m.val] } end end examples/chat/chat_server.rb Sunday, October 13, 13

83. Lattices; monotonic functions. Bloom Sunday, October 13, 13

84. class ChatServer include Bud include ChatProtocol state do table :nodelist

    channel :disconnect end bloom do nodelist <= connect.map { |c| [c.client, c.nick] } mcast <~ (mcast * nodelist).pairs { |m,n| [n.key, m.val] } nodelist <- disconnect.map { |c| [c.client, c.nick] } end end examples/chat/chat_server.rb Sunday, October 13, 13

85. Non-monotonic; not eventually consistent. Bloom Sunday, October 13, 13

86. bloom do mcast <~ stdio do |s| [@server, [ip_port, @nick,

    Time.new.strftime("%I:%M.%S"), s.line]] end stdio <~ mcast { |m| [pretty_print(m.val)] } end examples/chat/chat.rb Sunday, October 13, 13

87. KV Store. Bloom Sunday, October 13, 13

88. module BasicKVS include KVSProtocol state do table :kvstate, [:key] =>

    [:value] end bloom :mutate do kvstate <+ kvput {|s| [s.key, s.value]} kvstate <- (kvstate * kvput).lefts(:key => :key) end bloom :get do temp :getj <= (kvget * kvstate).pairs(:key => :key) kvget_response <= getj do |g, t| [g.reqid, t.key, t.value] end end bloom :delete do kvstate <- (kvstate * kvdel).lefts(:key => :key) end end kvs/kvs.rb Sunday, October 13, 13

89. module ReplicatedKVS include KVSProtocol include MulticastProtocol include MembershipProtocol import BasicKVS

    => :kvs bloom :local_indir do kvs.kvdel <= kvdel kvs.kvget <= kvget kvget_response <= kvs.kvget_response end bloom :puts do # if I am the master, multicast store requests mcast_send <= kvput do |k| unless member.include? [k.client] [k.reqid, ["put", [@addy, k.key, k.reqid, k.value]]] end end kvs.kvput <= mcast_done do |m| if m.payload[0] == "put" m.payload[1] end end # if I am a replica, store the payload of the multicast kvs.kvput <= pipe_out do |d| if d.payload.fetch(1) != @addy and d.payload[0] == "put" d.payload[1] end end end bloom :dels do mcast_send <= kvdel do |k| unless member.include? [k.client] [k.reqid, ["del", [@addy, k.key, k.reqid]]] end end kvs.kvdel <= mcast_done do |m| if m.payload[0] == "del" m.payload[1] end end kvs.kvdel <= pipe_out do |d| if d.payload.fetch(1) != @addy and d.payload[0] == "del" d.payload[1] end end end end kvs/kvs.rb Sunday, October 13, 13

90. CALM Analysis Sunday, October 13, 13

91. Label asynchronous, non-monotonic. CALM Analysis Sunday, October 13, 13

92. Identify where coordination is needed. CALM Analysis Sunday, October 13,

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93. The Conclusion Sunday, October 13, 13

94. Prototype language. The Conclusion Sunday, October 13, 13

95. https://github.com/bloom-lang/bud https://github.com/bloom-lang/bud-sandbox Thanks! Questions? Sunday, October 13, 13